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Aniej

macrumors 68000
Original poster
Oct 17, 2006
1,743
0
Aside from the constant banter on here about gaming, I am unclear about what the importance of 256MB SDRAM graphics card is versus the 128MB. Can someone help me understand the significance and where it would matter? Thanks.
 
When working with Video or even Photos, some applications utilize the video memory to help speed up processing. 3D Graphics uses video memory heavily such as Maya and the likes. CAD, those areas use video memory.
 
I am unclear about what the importance of 256MB SDRAM graphics card is versus the 128MB.

Video RAM in graphics cards is high-speed RAM that's local and specific to the graphics card (i.e., it can't be used or accessed as general system RAM). The data for the screen (or screens, if you have more than one monitor) is stored in this VRAM, so the card can output the graphics. The higher the resolution, the more VRAM is required. Using full-screen anti-aliasing (smoothing out the edges of graphics, normally used in games) will increase that amount. Textures are stored in the VRAM...these can be graphics for games, or windows in OS X. 3D models have their geometry stored in VRAM.

How much VRAM you should have depends on how graphically-intensive your needs are. Mostly this affects gaming, but if you were running a couple of 30" displays with lots of open windows on each, it's possible 128MB might not be enough (though I'd have to do some calculations to be sure). If you start running out of VRAM, the system swaps out stuff to main memory, which is relatively slow. The effects of this could be seen by stuttering animation when using Exposé, for example. But mostly it's about games which have lots of high-resolution textures, running on high-resolution screens with heavy anti-aliasing. That would chew up VRAM. If you don't game, it's unlikely you'd have to worry about it.

--Eric
 
When working with Video or even Photos, some applications utilize the video memory to help speed up processing. 3D Graphics uses video memory heavily such as Maya and the likes. CAD, those areas use video memory.


correct on 3D, CAD etc, wrong on photos......... video card has virtually Ø effect on 2D work, UNLESS of course, you're trying to display it on monster screen(s) @ very high rez. And even then, it only affects the ability to drive the displays, not the actual photos themselves
 
correct on 3D, CAD etc, wrong on photos......... video card has virtually Ø effect on 2D work, UNLESS of course, you're trying to display it on monster screen(s) @ very high rez. And even then, it only affects the ability to drive the displays, not the actual photos themselves

UNLESS you are running Aperture. It uses the GPU. The better the video, the better it runs.

Which is why the poster was correct, "some apps" do use it for photos.
 
UNLESS you are running Aperture. It uses the GPU. The better the video, the better it runs.

Which is why the poster was correct, "some apps" do use it for photos.

Yes, but Aperture ops are more speed-dependent on the speed of the GPU itself, rather than the amount of RAM on the card. As long as your image fits into the available texture RAM (and you'd have to have a pretty freaking huge image to not be able to fit it into even 128MB of RAM), the speed of any GPU-assisted filters/color ops is all about the pixel shaders on your card.

However, to address the OP's question, there's really no reason to skimp on video card RAM these days. With larger and larger displays (and more and larger windows being stored in texture RAM), plus the oncoming requirements of Quartz 2D Extreme (assuming it's turned on in Leopard) which will actually start drawing windows' contents on-GPU, the more RAM you have the better off you'll be.
 
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